Sanding attachment

ABSTRACT

The disclosure relates to an attachment for conventional vibratory sanders, which attachment includes a plate adapted to be attached to the power section of such sander. The plate has attached thereto several mandrels of different configuration to receive shuts of abrasive material. The sander with the attachments thereon may be used to clean and smooth holes or slots of various shapes and sizes etc.

United States Patent [191 Brown SANDING ATTACHMENT [76] Inventor: Roland Clough Brown, 425

Stratford Ct., Del Mar, Calif. 92014 [22] Filed: Oct. 18, 1971 [21] Appl. No.: 190,167

[52] US. Cl 51/170 R [51] Int. Cl B24b 23/00 [58] Field of Search 51/170 R, 170 L, 170 MT 5 6] References, Cited UNITED STATES PATENTS 2,307,43l l/l943 Tilden et al 5 l/l70 TL 2,958,355 ll/l960 Young. 5l/l70 R X Mar. 12, 1974 3,530,577 9/1970 Franklin et al. 5 H170 MT X Primary ExaminerOthell M. Simpson 5 7 ABSTRACT 1 Claim, 6 Drawing Figures i fff kg? SANDING ATTACHMENT The invention relates to a new and useful, electric or other power-driven, sanding attachment and, in particular, to a Keyhole Sanding Attachment for use by a woodwork or other material finisher, seeking a clean, smooth base for a selected surface finish to be applied later after working in keyholes, slots, holes, etc., or intricate combinations thereof, in grille or panel scrollwork of wood, metal or other materials with the attachment.

The present invention is directed toward the improved usefulness of the attached, abrasive T-fingers of various shapes and sizes to permit insertion of the selected abrasive surface into such small openings as simple holes and slots or the curves of intricate scrollwork needing cleaning and smoothing before final finish coating of the material.

It is the primary object of the invention to provide a power-driven sanding attachment to clean and smooth the edge contour surfaces of simple or intricate patterns in the scrollwork of grilles, panels, etc.

A secondary object provides for the speedy accomplishment of the task without the slow labor and fatigue of hand work in finishing or refinishing scrollwork of grilles, panels. etc.

A further object providesfor the easy and quick conversion of the regular sander for plane surface finishing to the Keyhole Sanding Attachment for edge controur surfaces in scrollwork finishing or refinishing of grilles, panels, etc.

Again another object provides for an automatic variation in pressure on the point of application of the T- fingers abrasive surface with the work as the T-finger moves in and out of the slot being cleaned or smoothed.

Also another object provides up to four different I shapes and sizes of T fingers that may be affixed to the attachment at one time to meet variations in shape of scrollwork pattern contours by utilizing different T- fingers in succession as necessary.

Then another object providesfor quick and easy fitting and replacement of worn out abrasive sheets by means of the slit in the T-fingers companion slipout mandrel.

Another important object providesfor the positive clamping of the abrasive surface flap ends by means of pressure on the surface of the partially-split mandrel when inserted in its T-finger and spread slighly by the set screw, thus, preventing slippage or movement of the abrasive surface when the sanding attachment is in operation.

Yet another object provides an attachment that requires no maintenance of .its component parts.

Still another object provides for the use ofthe powerdriven section of the rectangular sander with its plug cord, handle and on-off switch for driving the Keyhole Sanding Attachment with the savings in cost of the power section.

Other ancillary objects will be apparent from the fol lowing description when read in the light of the drawing in which:

FIG. 1, is a plan view of the connector plate' with the various mandrels attached thereto;

FIG. 2 is a longitudinal sectional view of FIG. 1 taken along line 2-2 thereof with the sander illustrated in broken lines;

' FI GTS, is a sectional view of figure taken along line FIG. 4, is a sectional view of FIG. 1 taken along line 4-4;

FIG. 5, is a sectional view of FIG. 1 taken along line 5-5; and

FIG. 6, is a sectional view of FIG. 1 taken along line 6-6.

The power-driven sanding attachment consists of a flat plate connector 2, instead of the regular sanding plate of the sander, with holes therein for two large machine screws 3 to fasten it rigidly to the power section of the sander l with its handle 10 and on-off switch 1, and four T-fingers 4, placed in any or all positions at right angles to each other in the plane of the connector, with each one fastened thereto by a small machine screw 3 and two stud guide pin holes, one at each end of the cross of the T which fit over stud guide pins 5 correspondingly located in the connector plate and hold the T-finger rigidly in position when the small machine screw is inserted into hole 13 and drawn up tight.

Each T-finger includes a partially split mandrel 15 around which and abrasive sheet 7 is placed. The ends 14 of the sheet isinserted into the slot of the mandrel and confined therein by means of a companion insert 6 and set screw 8. The connector and T-fingers are usually made of metal to match the sander power section.

The invention is advantageously used by a factory, shop or home work bench with a power-driven sander on hand. The T-fingers of various shapes and sizes enables the sanding attachment to be utilized to clean and smooth holes, slots, curves, etc., in simple or intricate patterns of scrolls on grilles or panels when the large regular, rectangular sander plate is impossible to use.

Various shapes and sizes of T-fingers are contemplated as a stepped thin plate; Aainch square and Vsinch %inch, /ainch X %inch, %inch X 'Vsinch rectangular;

similar equilateral triangle sizes; and Vainch, 35inch,

Aainch and %inch diameter round sizes as well as pyramidal and conical ones, all except the stepped thin plate fitted with a companion letter-marked mandrel, and all of them with geometric surface shapes that are capable of flat surface development.

To assemble the Keyhole Sanding Attachment, remove the regular sander plate, then attach the flat plate connector with as many T-fingers as planned for the work to be done by means of two large machine screws. Each selected T-finger is fixed to the plate by aligning the two stud guide pin holes over the corresponding stud guide pins located in the plate connected at each of the four. T-finger locations at right angles to one another,and then inserting and tightening the small machine screw. As many as four different shape and size T-fingers may be attached to the plate connector at one inserted lengthwise from the T end to press against the flaps, thus holding the abrasive surface securely in place during the work. A set screw at the cross of the T end of the mandrelis tightened with a screw driver to expand the mandrel slightly inside the T-finger and rigidly hold the covering abrasive surface during operatron.

To dismantle, remove the two large machine screws and replace the regular sander plate, dismantling such T-fingers as desired by loosening the set screw of the mandrel, removing the mandrel and the worn out abrasive surface only if replacement is necessary for the next job. The sander without attachment is then read for regular fiat surface sanding.

To put the Keyhole Sanding attachment to use, assemble the T-fingers desired for the work at hand on the flat plate connector and attach it to the power section by means of the two large machine screws, making sure all set and machine. screws are tight. Place the work in a vice or otherwise clamp. Plug in the sander power section. Press ON button of power section near handle and proceed with the work, utilizing T- fingers that fit the grille work. To discontinue use, press OFF switch near handle. Unplug the sander power section. After use, the attachment is dismantled or laid aside for later use. Worn abrasive surfaces are replaced.

The Keyhole Sanding Attachment, when assembled, is a one piece attachment, quickly fitted to the powerdriven section of a regular sander with its handle and on-off switch by means of two large machine screws. It requires no maintenance, except cleaning and oiling to prevent rusting and the replacement of worn out abrasive surface sheets, as it has no wearing parts. It is inexpensive to own. Anyone who can operate a sander can fit and operate the attachment. The attachment is usually made of metal with a nickel or chrome finish.

The Keyhole Sanding Attachment is bought separately from the power-driven sander, dismantled. When used, the regular sanding-plate of the sander is removed and the flat plate connector is then fitted to the power section by means of two large machine screws.

The T-fingers selected for the work to be done are then fitted with abrasive material such as sandpaper or emory cloth and held in place by insertion of its longitudinally, partially-split mandrel, marked for convenience with letters A,B,C and D, as indicated by reference character 12, all the way, making sure to entrap the flap ends of the abrasive material being used, and then turning the set screw to spread the mandrel halves slightly to tighten them against the interior surface of the T-finger. The T-fingers so prepared for the work are then affixed to the flat plate connector in any of the four positions available by snapping the cross of the T guide pin holes on the corresponding twostud guide pins, then inserting the small machine screw and draw ing it up tight.

When all selected T-fingers are in place on the flat plate connector, the cleaning or smoothing work is begun by plugging in the electric cord, grasping the connected from the power section of the sander as desired.

The attachment may be used in school manual training classes, home workshops, shops, factories and'in the trade wherever the power-driven sander is needed from student training to professional practice as a useful tool. Practice in cutting the abrasive surface sheets to size to fit the various T-fingers is a useful exercise in the plane development of the surfaces concerned for all users. Skillful use of the Keyhole Sanding Attachment comes with but little practice.

For illustrative purposes one form of the invention is shown on the drawing but other forms of the attachment are contemplated by the description included herein, and the assembly applicable is disclosed; however, the invention is not limited to the details or the exact forms shown or described, as major deviations in the shape and size of the attachment from the illustrated power-driven sander form are possible without modifying the principles involved. In addition, pyramidal and conical T-fingers are contemplated for special purposes to augment the selection of T-fingers available; in fact, any shape of T-finger whose surface may be developed into a plane is possible since an abrasive sheet may be cut and fitted to the exact surface of the T-finger to be covered.

I claim:

1. The combination with a power sander having a vibratory power section, of a sanding attachment attachable thereto: The attachment comprising; a generally rectangular, rigid, flat connector plate for attachment to said power section; said connector plate having apertures therein for receiving fastening means for interconnecting said plate and power section; said plate having a series of threaded apertures selectively spaced along the periphery thereof; a series of generally elongated finger-like hollow mandrels having means thereon for attaching same to said plate via siad series of threaded apertures; each of said mandrels being of different geometrical cross-sectional configuration and having a longitudinal slit therein; abrasive sheet means for encampassing each said mandrel with the ends there positioned within said slit; and elongated companion insert means snugly receivable within eachand of of like conformation of said mandrel and engageable with said ends of said sheet to secure the same to said mandrel. 

1. The combination with a power sander having a vibratory power section, of a sanding attachment attachable thereto: The attachment comprising; a generally rectangular, rigid, flat connector plate for attachment to said power section; said connector plate having apertures therein for receiving fastening means for interconnecting said plate and power section; said plate having a series of threaded apertures selectively spaced along the periphery thereof; a series of generally elongated finger-like hollow mandrels having means thereon for attaching same to said plate via siad series of threaded apertures; each of said mandrels being of different geometrical cross-sectional configuration and having a longitudinal slit therein; abrasive sheet means for encampassing each said mandrel with the ends there positioned within said slit; and elongated companion insert means snugly receivable within each and of of like conformation of said mandrel and engageable with said ends of said sheet to secure the same to said mandrel. 